Abstract
In most forming processes based on tailored blanks, the tool material remains the same as that of sheet metal blanks without tailored properties. A novel concept of lightweight construction for deep drawing tools is presented in this work to improve the forming behavior of tailored blanks. The investigations presented here deal with the forming of tailored blanks of dissimilar strengths using tailored dies made of two different materials. In the area of the steel blank with higher strength, typical tool steel is used. In the area of the low-strength steel, a hybrid tool made out of a polymer and a fiber-reinforced surface replaces the steel half. Cylindrical cups of DP600/HX300LAD are formed and analyzed regarding their formability. The use of two different halves of tool materials shows improved blank thickness distribution, weld-line movement and pressure distribution compared to the use of two steel halves. An improvement in strain distribution is also observed by the inclusion of springs in the polymer side of tools, which is implemented to control the material flow in the die. Furthermore, a reduction in tool weight of approximately 75% can be achieved by using this technique. An accurate finite element modeling strategy is developed to analyze the problem numerically and is verified experimentally for the cylindrical cup. This strategy is then applied to investigate the thickness distribution and weld-line movement for a complex geometry, and its transferability is validated. The inclusion of springs in the hybrid tool leads to better material flow, which results in reduction of weld-line movement by around 60%, leading to more uniform thickness distribution.
Highlights
Due to the increase in demand of different strengths in structures, several types of tailored blanks like tailor-rolled or tailor-welded exists as mentioned in Merklein et al [1]
The main benefits of these blanks exist in the possibility of weight reduction and in the capability to reduce joining processes in the press shop
Due to the weld line on the surface and shifts of thickness, tailored blanks are used as structural parts in the body-in-white of cars for improving crash performance
Summary
Due to the increase in demand of different strengths in structures, several types of tailored blanks like tailor-rolled or tailor-welded exists as mentioned in Merklein et al [1]. The possibility to select different sheets of different thickness, strength, and material properties enables the designer to distribute the material optimally. This leads to lighter structures, higher strengths, and joining before forming, which lowers the production costs [2]. The main benefits of these blanks exist in the possibility of weight reduction and in the capability to reduce joining processes in the press shop. Due to the weld line on the surface and shifts of thickness, tailored blanks are used as structural parts in the body-in-white of cars for improving crash performance
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
